A Thin Quad Band FSS Based on Enclosed Cross Slots to Foster Gain in Multiband Applications

The reported work provides a thin-profile quad-band FSS which is designed as a sub-reflector to foster gain in satellite systems, detection systems for sensing traffic light and motion, short-range applications, broadcasting satellite, and direct broadcast satellite. The unit cell spans 0.08λO × 0.08AO × 0.012λo, where, λO is the wavelength corresponding to the lower cut-off frequency. It consists of four stop bands with resonance notes located at 6.6 and 7.98, 9.93 and 12.6, and 20.68 GHz. The FBW of these bands are respectively 60, 9.7, 11.4, and 28.6 %. In addition, fourfold symmetry of the structure results in an excellent response that is insensitive to polarisation and a steady response in both the TE and TM modes. Full wave simulation is used to analyse the structure, and then the measurement of a fabricated prototype is used to verify the results. Multiband wireless technologies can benefit from the reported quadband FSS layer for enhancing gain.